Trad Gang

Had this on the shooter forum:

Can you guys explain to me the importance of heavy weight up front on an arrow.

I read alot of post about adding inserts and heavy broadheads. But seems to me that it would slow down the arrow and cause a good bit of drop in the arrow.

Thanks, I'm still learning!

To make it as simple as possible, tests have shown that a arrow will penetrates farther if it is pulled through its target rather than being pushed through. I beleive it has a lot to do with arrow (oscellation ?)when it contacts the target.

Earl has got it. i have proven it to myself numerous times over the past six years or so. Fpr me, the arrow weight would be the same, 10 grains per pound of bow weight, more or less. A 600 grain arrow with 200 grains up front has significantly out penetrated similar 600 grain weight arrows I used to shoot from much heavier bows with only 125 grains up front.

Tracy if you want to make some EFOC arrows take a look a Victory Archery arrow HV-3 series they they are 300 to 400 spine and are all in the 6.4 to 6.7 gpi weight.

First order of business is to learn how to properly tune your arrows.This will affect performance more than anything.

After that,high FOC can increase performance and there is no nose diving.Again,learn how to tune before you get serious about this stuff.Since adding weight to the front end weakens the dynamic spine of the arrow( makes it act weak)you have to go up one or 2 spine groups to achieve the high FOC and still be in tune.

It helped me,when switching to carbons,to tune up a regular set with more normal weight heads,then I had a base of reference to increase spine and point weight on the next set of arrows.

If you are just starting out,learning the art of tuning is very important and I personally would get that figured out without the complications of more advanced stuff.After you have a complete understanding of tuning,you could move on from there.See the tuning information at  www.bowmaker.net (http://www.bowmaker.net)

He also hits briefly on FOC.

Jim B makes makes a point. I just figured that anyone messing with High FOC was already skilled with tuning a arrow to there bow?

Thanks guys. No I haven't figured out the tuning stuff yet. I thought that was part of the whole process of tuning. I just seen alot of stuff about inserts and broadheads.
Just got a (new to me) bow from a fellow trad member. I had been practicing with a borrowed ben pearson.
This one is a Jordan Stalker 3pc takedown 52#@28"

I will ck out bowmaker.net

Well,adding or taking away point weight does enter to the tuning aspect.It weakens or stiffens the dynamic spine as do changes in shaft length.

Normal FOC was always considered to be something like 11-15 %.These days some people experiment with and test the benefits of much higher percentages of FOC and I'm told by some smarter than me,that performance increases don't start to show till 19% and above.

A lot of spine recommendations are considering normal FOC and standard weight heads like 125 gr.When you talk about heavy weight up front,most would probably think of 250 grs and on up.Almost any weight can be made to work if you get the right combination of front end weight and shaft stiffness.

I haven't personally used it but a lot of people use Stu's Calculator which is a program you can download and it will give you suggestions on shaft spine,length and point weight.Most say it is very accurate if the correct numbers a punched in.You would still want to shoot and check tuning to verify.You could post a question about Stu's Calculator and I'm sure someone could help you.

Good luck,you are in for a lot of fun.

trcytylr, there's a lot of hype relative to extreme weight-forward arrows, and a lot of flawed logic to support certain claims. This trend mostly resulted from the use of carbon arrows. They tend to be so light that you need a very heavy point to get decent arrow weight, and they tend to be so stiff that they need to be shot full-length with a heavy point to get them to tune properly from moderate draw weight bows.

The fact is, if your arrow is front-heavy to any degree, and if it's tuned properly to your bow, it will shoot and penetrate just fine. We've been doing it this way since way before carbon was used for shafts, and there are millions of dead animals to testify to "standard" traditional archery setups.

Perfect arrow flight trumps every other consideration. Get there first, and then play with things like EFOC if you like to tinker. Extreme arrows are useful for extreme situations, but for the vast majority of us such measures are not necessary for our hunting in the USA. Now, if you're going to Africa or Australia...

There is also lot of proof through hard work and testing that proves it's effectiveness and yes carbon arrows make it easier to do.

If your truly interested in FOC and EFOC read the Ashby threads in full and ask any questions you have on here.  I went thru them and found a way to obtain EFOC in a 584 grain arrow.  Was it vital to my shooting.  Not really.  Do I feel a lot more confident in my ability to penetrate an elk.  Yes I do and confidence is a big part of good shooting for me.  I personally would not hunt with an arrow that is not optimized.  Perfect arrow flight using an FOC optimized arrow makes it so a 45 lb bow shot arrow hits like it was a standard arrow shot from a 65 lb bow.

Just my way of doing things.  Millions of animals have been killed without EFOC arrows being used.

QuoteOriginally posted by Ragnarok Forge:
 Perfect arrow flight using an FOC optimized arrow makes it so a 45 lb bow shot arrow hits like it was a standard arrow shot from a 65 lb bow.

Clay....where did you get that documented fact?

Not trying to be a smart alec....but just want to know where that claim came from and if it is fact.  There are a lot of claims being made lately that are unfounded and being parroted all over the place....and this leads folks to use the wrong equipment only 'thinking' that they are good to go when the are not..  Its a big claim to say the same 45# bow will 'hit like' the same designed 65# bow drawn to the same length.

Where did you get the fact that a simple change in weight distribution on an arrow would make up for a 20# draw weigh reduction?

:)

Terry,

Read thru the latest Ashby Report on the 40 lb bow and it's results.  I used his information from that report for that statement.  I would love to have the time and money to prove it myself with scientific research.  

Thanks for keeping me honest by the way.  I have always appreciated that about this site and your moderation of it. It isn't just recently that folks make a lot of claims without support.  Just look at the KE = penetration that is being pushed by the compound industry as the end all and be all for one great example of this trend.

Clay....1st, thanks for the civil response...

There is no way a 45# bow shooting 10 grains per pound (450 grains) with an FOC of 25 or 30% is going to shoot with the same authority as a 65# bow shooting 10 grains per pound (650 grains) with an FOC of 15% (both at the same draw length).  Aint gonna happen...and I don't believe can be proven no matter the money spent.

Again, not being a smart alec,....just don't want folks to believe in some magical FOC and a light weight bow that they can conquer the world more efficiently than with a 20 pound heavier bow with normal FOC.

FOC is a SMALL increment in the grand scheme of thing.  MANY things are MUCH more important to killing animals than what percentage of the weight  forward as long as its 12% or above with broadheads. (the last statement concerning 12% is my opinion on shooting Bheads under adverse conditions afield.  I feel 12% FOC is MINIMUM and 15-18% is much more stable with the hunting shots based on different shooting angles, body contortions, terrain features, weather, etc.)

QuoteOriginally posted by Terry Green:
Clay....1st, thanks for the civil response...

There is no way a 45# bow shooting 10 grains per pound (450 grains) with an FOC of 25 or 30% is going to shoot with the same authority as a 65# bow shooting 10 grains per pound (650 grains) with an FOC of 15% (both at the same draw length).  Aint gonna happen...and I don't believe can be proven no matter the money spent.

Again, not being a smart alec,....just don't want folks to believe in some magical FOC and a light weight bow that they can conquer the world more efficiently than with a 20 pound heavier bow with normal FOC.

FOC is a SMALL increment in the grand scheme of thing.  MANY things are MUCH more important to killing animals than what percentage of the weight  forward as long as its 12% or above with broadheads. (the last statement concerning 12% is my opinion on shooting Bheads under adverse conditions afield.  I feel 12% FOC is MINIMUM and 15-18% is much more stable with the hunting shots based on different shooting angles, body contortions, terrain features, weather, etc.)

You just asked the poster before you for proof.  Where's yours? Statements like, "I feel.." just don't cut it when compared to the testing done by Ashby.

Str8Arrow,

Answer....simple, momentum created by the 650 grain arrow from the 65 pound bow FAR exceeds the 450 grain arrow from the 45 pound bow that FOC will NOT make up. "I feel" is my opinion based on MY testing and based on 12% as a minimum.  Is only ONE man allowed to test and report?

Where's YOUR proof disputing that?  Where is YOUR testing?

Your quote ..."Statements like, "I feel.." " was ONLY directed to what I feel is minimum for broadheads and hunting....had nothing to do with the facts I stated above.....yes facts until proven wrong.

If you read Ashby's studies, you'll see that momentum is more easily redirected when it is centered further back on the arrow. Even without doing the studies myself, it makes perfect sense that an arrow that deflects more (lower FOC), will not penetrate as well as an arrow that deflects less (higher FOC).  Add in the penetration measurements taken from shots from the 40 lb vs 65 lb bow and it makes sense.

Where's Doctor Ed?
Maybe he can explain some of this.

How come he doesn't post here anymore?   :confused:    :dunno:

I thought I should add that nobody is going to prove anything in regards to this subject. One can accumulate evidence that supports a particular theory and I would say that Ashby has gathered a huge amount of evidence to support his theories.  If you can direct me to anyone else who has recorded a similar amount of evidence with a different conclusion, I'd love to read it. I'm always looking for data that supports hunting a better way.

QuoteOriginally posted by Str8Arrow:
If you read Ashby's studies, you'll see that momentum is more easily redirected when it is centered further back on the arrow. Even without doing the studies myself, it makes perfect sense that an arrow that deflects more (lower FOC), will not penetrate as well as an arrow that deflects less (higher FOC).  Add in the penetration measurements taken from shots from the 40 lb vs 65 lb bow and it makes sense.

I sure don't see that in the momentum aspect...maybe there's some contradiction there???

1st a person claims momentum is king, and then he does not?  Again...where is the facts or proof.  Where are YOUR tests not someone else's?  I've done my own....and on LIVE animals and 3 different target mediums.  I cannot find where a 45# bow exceeds a 65# bow at 10 grains per pound period.

Now show me the proof....YOUR proof, not someone else's 'theories'.  The momentum numbers don't lie, and neither do momentum vs FOC.  Show me EXACTLY where I'm wrong.....without smoke and mirrors.

SHOW ME where a 45# bow with 25% FOC exceeds a 65# bow same grain per pound with the 65# bow at 15% FOC with the same design bow and draw length.  PROVE IT to me....not theories about it.  PROVE IT. I'd love for my 70@ bows to 'hit like' 90#ers.

QuoteOriginally posted by Terry Green:

1st a person claims momentum is king, and then he does not?

I'm not sure who said it was king and then said it wasn't. I say that momentum is a better indicator of penetration potential than KE is. Potential of course, can be unrealized - especially if redirected by a bone.

QuoteAgain...where is the facts or proof.

Ashby has provided a huge amount of data that supports his theories. Like I said, proof is not going to happen - not on the internet.

QuoteWhere are YOUR test not someone else's?

I've done no formal testing with data that was critically analysed. All I have is 5 years of shooting High and extreme FOC arrows into animals with very positive success.  However, there is nothing wrong with relying on the substantial testing done by Ashby.

QuoteI've done my own....and on LIVE animals and 3 different target mediums.  I cannot find where a 45# bow exceeds a 65# bow at 10 grains per pound period.

Point me to the data so I can see if it make sense to me.

All I have is 25 years of KILLING animals with 18% FOC with GREAT success....and measuring penetration in 3 different target mediums with different weight bows.

 

QuoteOriginally posted by Terry Green:
     

QuoteOriginally posted by Str8Arrow:
If you read Ashby's studies, you'll see that momentum is more easily redirected when it is centered further back on the arrow. Even without doing the studies myself, it makes perfect sense that an arrow that deflects more (lower FOC), will not penetrate as well as an arrow that deflects less (higher FOC).  Add in the penetration measurements taken from shots from the 40 lb vs 65 lb bow and it makes sense.

I sure don't see that in the momentum aspect...maybe there's some contradiction there???

1st a person claims momentum is king, and then he does not?  Again...where is the facts or proof.  Where are YOUR tests not someone else's?  I've done my own....and on LIVE animals and 3 different target mediums.  I cannot find where a 45# bow exceeds a 65# bow at 10 grains per pound period.

Now show me the proof....YOUR proof, not someone else's 'theories'.  The momentum numbers don't lie, and neither do momentum vs FOC.  Show me EXACTLY where I'm wrong.....without smoke and mirrors.

SHOW ME where a 45# bow with 25% FOC exceeds a 65# bow same grain per pound with the 65# bow at 15% FOC with the same design bow and draw length.  PROVE IT to me....not theories about it.  PROVE IT. I'd love for my 70@ bows to 'hit like' 90#ers. [/b]

Again...PROVE ME WRONG....PLEASE!!!!!!!!!!! I want my 70#ers to 'hit like" 90#ers please prove it to me!!!! ( I don't think you can)

Why are you so hung up on this "prove me wrong"? Don't you know that nothing can be proved absolutely? Do you realize there is a whole segment of society that believes the earth is flat and you can go to their web forum and I'll guarantee you that you will not be able to prove to them that it is not.

I'm not asking you for proof. I'm asking you for data that I can analyse critically. I want to see if your testing was complete or if you missed something or made an error or two in your testing or conclusions. After reading Ashby's studies, I was very impressed by the thoroughness of the data and conclusions drawn. I'm really hoping if others have contradictory data, that they simply let us study it.

QuoteOriginally posted by Str8Arrow:
You just asked the poster before you for proof.  Where's yours?  

QuoteOriginally posted by Str8Arrow:

I'm not asking you for proof.  

Looks like more contradiction......

Until it is PROVEN....I stand by my signature line...Until then, I'll be waiting for a common sense answer.

Sorry....I meant to quote you but edited your post by mistake.

A lot of people don't realize that perfect arrow flight is near the top of Ashby's list in order of importance.

He says,"Poor flight squanders arrow performance.
 You should spare neither effort nor expense in achieving absolutely perfect arrow flight.Even with every other factor in place,without good arrow flight you'll still have poor arrow performance."

QuoteOriginally posted by JimB:
A lot of people don't realize that perfect arrow flight is near the top of Ashby's list in order of importance.

He says,"Poor flight squanders arrow performance.
 You should spare neither effort nor expense in achieving absolutely perfect arrow flight.Even with every other factor in place,without good arrow flight you'll still have poor arrow performance."

Amen....LOTS of folks here are preaching that as well....and have been for a LONG time.

I agree. EFOC is only a part of his studies and recommendations. In fact, he recommends shooting the heaviest draw weight you can accurately shoot at hunting distances. Even though his data demonstrates that you can optimize an arrow's penetration with EFOC, he's an advocate of using as much fire power as possible. He'd like you to shoot the heavy draw weight with the optimized arrow. One of his beliefs is that there is no such thing as too much penetration when bowhunting.

QuoteOriginally posted by Str8Arrow:
[I see, in other words, you have no data to suport your view and want to protect the unknowing masses from the only data given in a thorough study on the subject.  This is good to know. It explains a lot. end quote.

What speak volumes is YOU have no proof OR data.....nor can prove me wrong even though I HAVE data.  I GAVE it to you....PROVE to me the 45#/65# claim...with DATA.

I just wanted to tune my little bow and arrows   :(

QuoteOriginally posted by Str8Arrow:
Why are you so hung up on this "prove me wrong"? Don't you know that nothing can be proved absolutely?

E = mv2/2

Isaac Newton and the prevailing laws of physics are on Terry's side here.

I had never heard of EFOC until a month ago when I dusted off my recurve and set about trying to tune things up.

However, the idea that you can take two arrows traveling at the same speed (for arguments sake) one 650 grains, and one 450 grains (roughly 30% lighter) and achieve the same impact energy by shifting the weight distribution of the arrow is... poppycock.

It may improve arrow flight in some arrows, thus aiding penetration somewhat, but that is not what was claimed.

This can easily be tested. Take the two bows and the two arrows. Use rubber blunts and shoot them at your car and check the size of the dents. No matter what you do to the FOC the heavier arrow + heavier draw weight bow will make a bigger dent.

Ok,  I think were missing some critical points in this discussion as it revolves around my earlier statement.  My statement was based on penetration optimized arrows for the 40 lb bow compared with standard nonpenetration optimized arrows with the 60 or 65 lb bow.  If you give the Ashby reports a thorough read you will see that this is their basis for research and reporting.  

Optimized arrows do not weight 10 gpp.  That number has nothing to do with the Ashby reports or arrow optimization.  Ashby uses standard, high and EFOC arrows that weigh over 630 grains in his testing. He uses arrows that are  optimized to allow for the best penetration possible, and similar weight sets that are not optimized.  All shot testing is on recently killed animals.  These arrows are tested against each other.  

I work as an engineer and have reviewed his numbers, his theories and their basis, and torn his entire process and practices to pieces looking for flaws.  There really are not any to be found with minor exceptions that don't change the results of his studies.  


Terry is 100% correct, if you shoot the 10 GPP arrows for both bows the light arrows don't even come close to mathching penetration of the heavier bow.  If you take a non optimized 650 grain arrow out of a 65 lb bow and a totally optimized 650 grain arrow from a 45 lb bow, your gonna be suprised at the results.  In most  cases the lighter bow will match and at times exceed the heavier bows penetration.  Ashby's testing supports this as well.

Terry you will never get your 70 lb bow to shoot like a 90 lb bow, the arrow weights are roughly the same so the arrows arc will be different between the two bows.  You can get the lighter bows optimized EFOC arrows to penetrate like the heavier one when it is shooting standard design FOC arrows.  

Ashby's testing is indicating that EFOC arrows are showing dramatic increase in penetration over standard arrows.  Terry is right here too.  10% more more FOC helps a bit.  20% more FOC makes a lot more difference than we all think.  I am excited to see how much in the next few Ashby reports.

My engineering based review of all this stuff, the laws of physics, and momentum equations as they apply to penetration all lean to EFOC and penetration optimization of your arrows as a great way for a light weight bow shooter to bring their penetration to a point where it will match a heavier bows using standard non optimized FOC arrows.

Important to understand that I am not arguing with anyone here.  I think the original poster was asking about FOC and how to tune for it.  Drop me a PM and I will be happy to tell you how I did it.  Terry has a great post or two on how to get there so search a bit and find them.  Those posts saved me a ton of work to find EFOC.

The momentum equation which is what defines the energy that is used by an object to achieve penetration does not square velocity which is where the KE equation fails as does the one noted in the thread above.  The statement that physics supports Terry's comments is correct.  Since Terry's statement covered different weight arrows instead of optimized arrows for one bow and standard arrows for the other.

mrjsl ......thanks.....haven't heard the work poppycock in a long time.

Yep, run the numbers over and over and over, ....they don't lie.

Someone got 'hung up' on when I said 'I feel'...and that comment was ONLY directed to what I feel is minimum FOC for broadheads and hunting....had nothing to do with the facts I stated above that statement.

Here we go again....

"If you take a non optimized 650 grain arrow out of a 65 lb bow and a totally optimized 650 grain arrow from a 45 lb bow, your gonna be suprised at the results. In most cases the lighter bow will match and at times exceed the heavier bows penetration."......                     Run the momentum numbers on those two arrows....too great to overcome with a simple weight distribution shift on the arrow.

OK......this one has run its course....back to hunting...